BIOL 2301 Lecture Notes - Lecture 17: Adenylyl Cyclase, Wild Type, Cyclic Adenosine Monophosphate
6 Sep 2016
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In prokaryotes, adjacent genes are often transcribed as a single unit. Promoter transcribes a number of gene, then transcription stops. One small mrna molecule of 3 genes. Polycistronic message: have three genes, three reading frames, translated into three proteins (doesn"t happen in eukaryotes) Allows coordinate gene regulation: if we regulate promoter, all three go up or down, if we degrade one gene, then all three go down. Operon: unit of genes regulated together in bacteria. A transcriptional activator can bind and turn gene expression on . Activators bind to dna near promoter, turns on transcription (turn gene on) Makes more likely for rna polymerase to attach to promoter and start transcribing. In positive feedback, the protein product of a gene turns on its own transcription. The protein that"s binding, is the protein made from the gene in question. Binds to activating site of its own promoter to amplify weak signal.
